Emotional dysregulation moderates the relation between perceived stress and emotional eating in adolescent military dependents

OBJECTIVE

Adolescent children of US service members (i.e., military-dependent youth) face unique stressors that increase risk for various forms of disinhibited eating, including emotional eating. Difficulties with adaptively responding to stress and aversive emotions may play an important role in emotional eating. This study examined emotion dysregulation as a potential moderator of the association between perceived stress and emotional eating in adolescent military dependents.

METHOD

Participants were military-dependent youth (N = 163, 57.7% female, Mage = 14.5 ± 1.6, MBMI-z = 1.9 ± 0.4) at risk for adult binge-eating disorder and high weight enrolled in a randomized controlled prevention trial. Prior to intervention, participants completed questionnaires assessing perceived stress and emotional eating. Parents completed a questionnaire assessing their adolescent's emotion dysregulation. Moderation analyses were conducted using the PROCESS macro in SPSS and adjusted for theoretically relevant sociodemographic covariates.

RESULTS

The interaction between adolescent perceived stress and emotion dysregulation (parent-reported about the adolescent) in relation to adolescent emotional eating was found to be significant, such that higher emotion dysregulation magnified the association between perceived stress and emotional eating (p = .010). Examination of simple slopes indicated that associations between perceived stress and emotional eating were strongest for youth with above-average emotion dysregulation, and non-significant for youth with average or below-average emotion dysregulation.

DISCUSSION

Findings suggest that greater emotion dysregulation may increase risk for emotional eating in response to stress among military-dependent youth at risk for binge-eating disorder or high weight. Improving emotion regulation skills may be a useful target for eating disorder prevention among youth who are at risk for emotional eating.

PUBLIC SIGNIFICANCE

Prior research has shown that adolescent military dependents are at increased risk for eating disorders and high weight. The current study found that emotion dysregulation moderated the relationship between perceived stress and emotional eating among military-dependent youth. There may be clinical utility in intervening on emotion regulation for adolescent dependents at particular risk for emotional eating and subsequent eating disorders.

Assessing Clinical Utility of Pharmacogenetic Testing in the Military Health System

INTRODUCTION

Response to medications can differ widely among individual patients. Adverse drug reactions can lead to serious morbidity and mortality. Pharmacogenetic (PGx) testing can predict responses to medications and increased risks of adverse events where the genetic basis is understood. Several published manuscripts suggest positive impacts of systematic preemptive PGx testing. However, few studies have been conducted on PGx implementation in the Military Health System (MHS).

MATERIAL AND METHODS

A cross-sectional study of adult beneficiaries in a primary care clinic at a large military treatment facility was conducted in 2022. Participants underwent PGx genotyping of CYP2C19 and CYP2D6 genes at the Defense Health Agency Genetics Reference Laboratory. Participant medication lists were compared to the current Clinical Pharmacogenetic Implementation Consortium (CPIC) PGx gene-drug guidelines to assess potential actionability of these results.

RESULTS

Genotyping of CYP2C19 and CYP2D6 in 165 MHS beneficiaries (mean age: 65 years) revealed that 81.2% of participants had at least one abnormal PGx finding. Among those with an abnormal PGx result, 65% were taking a medication listed on the CPIC website with an association with the particular gene in which the finding was identified. In addition, 78% of all of the participants in the study were taking at least one medication that is metabolized by CYP2C19 or CYP2D6 with associated CPIC guidelines.

CONCLUSIONS

Pharmacogenetic testing for CYP2C19 and CYP2D6 identified a substantial proportion of MHS patients at a single center who could benefit from evaluation of current medication regimens based on the CPIC guidelines. Individualized medical management may be warranted to a greater degree than previously recognized based on the findings given possible differences in medication metabolism. Many MHS beneficiaries already take medications metabolized by CYP2C19 and CYP2D6, and a substantial proportion may be at risk for preventable adverse events for medications metabolized by these enzymes. While preliminary, a large number of actionable polymorphisms among a relatively small set of individuals taking at-risk medications suggest that implementing PGx testing in clinical practice may be beneficial in the MHS with appropriate clinical infrastructure.

Catecholamine-induced hypertensive crises: current insights and management

Phaeochromocytomas and paragangliomas (PPGLs) release catecholamines leading to catecholamine-induced hypertensive (CIH) crises, with blood pressure greater than or equal to 180/120 mm Hg. CIH crises can be complicated by tachyarrhythmias, hypotension, or life-threatening target organ damage while treatment remains undefined, often requiring co-management between endocrinologists and cardiologists. Furthermore, biochemical diagnosis of a PPGL as a cause of a CIH crisis can be difficult to identify or confounded by comorbid conditions, potentially resulting in misdiagnosis. Here, we combine relevant evidence, 60 years of collective clinical experience, insights derived from assessing over 2600 patients with PPGL, and supplementary outcomes from 100 patients (treated at the National Institutes of Health) with a CIH crisis to inform diagnosis and treatment of CIH crises. Recognising that disparities exist between availability, cost, and familiarity of various agents, flexible approaches are delineated allowing for customisation, given institutional availability and provider preference. A CIH crisis and its complications are readily treatable with available drugs, with effective intervention defining an avenue for mitigating consequent morbidity and mortality in patients with PPGL.

A health systems assessment of genetic counseling in cardiovascular care in a large health system: Adherence to genetics recommendations in the Military Health System

Genetic counseling and genetic testing are important tools for diagnosis, screening, and employment of effective medical management strategies for hereditary cardiovascular diseases. Despite widespread recognition of the benefits of genetic counseling and testing in cardiovascular care, little is published regarding their use in large healthcare systems. We conducted a retrospective cross-sectional study using administrative claims data in the US Military Health System to assess the state of recommended genomic counseling in clinical cardiovascular care. Logistic regression models were used to examine associations of genetic counseling among beneficiaries with hereditary cardiovascular conditions. Approximately 0.44% of beneficiaries in fiscal year 2018 had a diagnosis of a hereditary cardiovascular condition. Among the 23,364 patients with a diagnosis of hereditary cardiovascular disease, only 175 (0.75%) had documented genetic counseling and 196 (0.84%) had documented genetic testing. Genetic counseling did not differ by race, sex, service, or diagnosis. Age group, Active Duty status, rank as a proxy for socioeconomic status, and geographic location contributed significantly to the likelihood of receiving genetic counseling. These findings suggest that genetic counseling is underutilized in clinical cardiovascular care in the Military Health System and may be more broadly, despite expert consensus recommendations for its use and potential life-saving benefits. Unlike previous studies in the US civilian health sector, there did not appear to be disparities in genetic counseling by race or sex in the Military Health System. Strategies to improve care for cardiovascular disease should address the underutilization of recommended genetics evaluations for heritable diagnoses and the challenges of assessing use in large health systems studies.

Associations among alexithymia, disordered eating, and depressive symptoms in treatment-seeking adolescent military dependents at risk for adult binge-eating disorder and obesity

PURPOSE

Evidence suggests that difficulties identifying and describing one's feelings, core components of alexithymia, are associated with attitudinal and behavioral symptoms of disordered eating; depressive symptoms also may underlie these associations. Specifically, research indicates that alexithymia is positively related to depressive symptoms, which in turn may promote both disordered-eating attitudes and certain disinhibited-eating behaviors (e.g., emotional eating). Findings also suggest that military-dependent youth with high weight may exhibit elevated depressive symptoms and disordered eating. As such, understanding associations among alexithymia, depressive symptoms, and disordered eating is particularly relevant for this vulnerable population.

METHODS

We examined 149 adolescent military dependents (14.4 ± 1.6y; 55.0% female; 20.0% non-Hispanic Black; BMIz: 1.9 ± 0.4) at high risk for binge-eating disorder and obesity in adulthood. Participants completed questionnaires assessing two components of alexithymia (difficulty identifying feelings [DIF] and difficulty describing feelings [DDF]), depressive symptoms, emotional eating, and trait anxiety; disordered-eating attitudes were assessed via semi-structured interview.

RESULTS

A series of regression-based models examined indirect relationships of DIF and DDF with disordered-eating attitudes and emotional eating through depressive symptoms. Bootstrapped 95% confidence intervals revealed a significant indirect path from each of the alexithymia components to disordered-eating attitudes via depressive symptoms; indirect paths to emotional eating were non-significant.

CONCLUSION

Results support the salience of depressive symptoms in the relationship between alexithymia and disordered-eating attitudes. Future research should utilize prospective designs and explore direct and indirect associations of alexithymia with other disordered-eating behaviors.

LEVEL OF EVIDENCE

Level III, evidence obtained from a well-designed cohort study.

Examination of the Interaction between Parental Military-Status and Race among Non-Hispanic Black and Non-Hispanic White Adolescents with Overweight/Obesity

OBJECTIVES

Adolescent military-dependents experience distinct risk and protective factors, which may necessitate additional clinical considerations. In civilian youth, overweight/obesity is associated with eating, internalizing, and externalizing difficulties, with some studies reporting more difficulties among non-Hispanic White (vs. non-Hispanic Black) youth. It is unknown if these disparities exist among adolescent military-dependents, or between civilian and military-dependent youth.

METHODS

Non-Hispanic Black (187 civilian, 38 military-dependent) and non-Hispanic White (205 civilian, 84 military-dependent) adolescents with overweight/obesity (14.7 ± 1.6 years; 73.9% girls; body mass index adjusted for age and sex 1.9 ± 0.5) completed a disordered-eating interview; parents completed a measure assessing their child's internalizing and externalizing difficulties. Multiple linear regressions examined parental military-status as a moderator of the relationship of participant race with eating, internalizing, and externalizing difficulties.

RESULTS

White civilian youth with overweight/obesity reported significantly greater disordered-eating than their Black peers (p < .001); there were no other significant racial differences. In all regressions, parental military-status significantly moderated the association between race and each dependent variable (ps < .047). Black military-dependents (vs. civilians) reported more disordered-eating and internalizing difficulties (ps = .01). White military-dependents (vs. civilians) reported fewer externalizing difficulties (p = .01).

CONCLUSIONS

Black adolescent military-dependents with overweight/obesity may experience more eating and internalizing difficulties (vs. civilians), a pattern not observed among White participants. Future work should examine if being a military-dependent and a historically marginalized racial group member accounts for these findings. Such data may inform providers of youth with intersecting minority identities.

The Relationship Between Anxiety, Coping, and Disordered-Eating Attitudes in Adolescent Military-Dependents at High-Risk for Excess Weight Gain

Adolescent military-dependents are an understudied population who face unique stressors due to their parents' careers. Research suggests that adolescent military-dependents report more anxiety and disordered-eating than their civilian counterparts. While anxiety symptoms predict the onset and worsening of disordered-eating attitudes, the mechanisms underlying this relationship remain unclear. One factor that may underlie this relationship, and be particularly relevant for military-dependent youth, is coping. Therefore, we examined adolescent military-dependents (N=136; 14.5±1.5 years; 59.6% female; BMI-z: 1.9±0.4) who were at-risk for adult obesity and binge-eating disorder due to an age- and sex-adjusted BMI ≥ 85th percentile and loss-of-control eating and/or elevated anxiety. Participants completed an interview assessing disordered-eating attitudes and questionnaires on anxiety symptoms and coping strategies at a single time point. Bootstrapping models were conducted to examine the indirect paths between anxiety symptoms and disordered-eating attitudes through five coping subscales (aggression, distraction, endurance, self-distraction, and stress-recognition). Adjusting for relevant covariates, no significant indirect paths through the coping subscales (ps > .05) were found in any models. General coping, non-specific to eating, may not be a pathway between anxiety symptoms and disordered-eating attitudes among adolescents. Future research should examine other potential mediators of this relationship.

Weight-Based Teasing and Metabolic Syndrome Components among Adolescent Military Dependents at Risk for Adult Obesity

Background: Among adults, weight stigma is associated with markers of poor cardiometabolic health. Although weight-based teasing (WBT) is common among youth with high body weight, few studies have examined its associations with cardiometabolic markers. Owing to unique stressors (e.g., parental deployment and frequent moves), military-dependent youth may be at particularly high risk for obesity, WBT, and poor cardiometabolic health. We, therefore, assessed associations between WBT and cardiometabolic health markers among adolescent military dependents presenting for a weight gain prevention trial. Methods: Participants underwent fasting phlebotomy; had fasting weight, height, and waist circumference measured; and completed assessments of WBT, anxiety, and loss-of-control eating. Multivariate analysis of covariance, adjusting for relevant covariates including demographics and body composition, was used to examine differences in metabolic syndrome (MetS) components (waist circumference, systolic and diastolic blood pressure, high-density lipoprotein cholesterol, triglycerides, and glucose) between youth reporting WBT and youth reporting no WBT. Bootstrapped models examined whether WBT mediated the relationship between BMIz and MetS components. Results: Data from 142 youth (57.7% female; 14.4 ± 1.6 years; 51.2% non-Hispanic White, 20.9% non-Hispanic Black; BMIz: 1.9 ± 0.4) were analyzed. WBT was not significantly associated with any MetS component. Relationships were observed between BMIz and all MetS components (except systolic blood pressure and glucose), although WBT did not significantly mediate these relationships (p's > 0.05). Conclusions: This study did not find support for a relationship between WBT and MetS components in adolescent military dependents at risk for adult obesity. Prospective research is needed to determine whether associations between WBT and adverse cardiometabolic outcomes emerge primarily in adulthood.

Permanent change of station moves and disordered-eating attitudes and behaviors in prevention-seeking adolescent military-dependents

OBJECTIVE

Military-dependent youth appear to be at greater risk for disordered-eating than their civilian counterparts. Permanent change of station moves (PCS-moves), typically occurring every 2-3 years, are commonly experienced by adolescent military-dependents. However, the links between PCS-moves and disordered-eating in this population have not been explored. We hypothesized that stress arising from PCS-moves may contribute to the development and/or exacerbation of disordered-eating.

METHODS

One-hundred-forty-nine adolescent military-dependents with overweight or obesity (59.7% female; 46.3% non-Hispanic White; 14.4±1.5 years; BMI-z: 1.9±0.4) completed measures before commencing an adulthood obesity and binge-eating disorder prevention trial for adolescents at-risk for both conditions due to BMI percentile ≥85th and loss-of-control (LOC)-eating and/or elevated anxiety symptoms. Disordered-eating attitudes and LOC-eating were assessed by semi-structured interview, and emotional eating was self-reported. Adjusting for relevant covariates, multiple linear regressions examined the unique association of PCS-move frequency with disordered-eating attitudes and disinhibited-eating behaviors.

RESULTS

PCS-move frequency was not significantly associated with either LOC-eating frequency (β = 0.09, p = .27) or emotional eating (β = -0.04, p = .62). However, PCS-move frequency was positively associated with disordered-eating attitudes (β = 0.17, p = .04), which appeared to be primarily driven by shape concerns (β = 0.21, p = .01).

DISCUSSION

Findings indicate that frequency of PCS-moves is related to disordered-eating attitudes, but not behaviors. Longitudinal research is needed to understand if PCS-moves prospectively relate to the onset and/or exacerbation of disordered-eating, and the relevance of disordered-eating attitudes as opposed to disinhibited-eating behaviors.

Sex differences in metabolic syndrome components in adolescent military dependents at high-risk for adult obesity

BACKGROUND

Metabolic syndrome in adolescence has been associated with adverse cardiometabolic outcomes in adulthood. Preliminary data suggest that boys may have worsened metabolic syndrome components compared to girls. Yet, little is known about the physical health of military dependents, a potentially at-risk population.

OBJECTIVE

Examine sex differences in metabolic syndrome components in a sample of adolescent military dependents.

METHODS

Participants were adolescents (N = 139; 14.4 ± 1.6 years; 45.3% male; 41.0% non-Hispanic White, 19.4% non-Hispanic Black; BMI-z: 1.9 ± 0.4) at-risk for adult obesity and binge-eating disorder due to an age- and sex-adjusted BMI ≥85th percentile and loss-of-control eating and/or elevated anxiety. A multivariate analysis of covariance was conducted to compare objectively measured metabolic syndrome components across boys and girls. Covariates were age, race, loss-of-control eating status, anxiety symptoms, and BMI-z.

RESULTS

Metabolic syndrome components differed by sex (P = .01). Boys had higher systolic blood pressure (P = .049), lower high-density lipoprotein cholesterol (P = .01), and higher glucose (P = .001) than girls. Waist circumference, diastolic blood pressure, and triglycerides did not differ between boys and girls (P > .05).

CONCLUSIONS

Future research should prospectively examine these relationships into adulthood. If the current findings are supported, prevention programs should consider targeting cardiometabolic health particularly among male adolescent military dependents.

CRISPR/Cas9-mediated introduction of the sodium/iodide symporter gene enables noninvasive in vivo tracking of induced pluripotent stem cell-derived cardiomyocytes

Techniques that enable longitudinal tracking of cell fate after myocardial delivery are imperative for optimizing the efficacy of cell‐based cardiac therapies. However, these approaches have been underutilized in preclinical models and clinical trials, and there is considerable demand for site‐specific strategies achieving long‐term expression of reporter genes compatible with safe noninvasive imaging. In this study, the rhesus sodium/iodide symporter (NIS) gene was incorporated into rhesus macaque induced pluripotent stem cells (RhiPSCs) via CRISPR/Cas9. Cardiomyocytes derived from NIS‐RhiPSCs (NIS‐RhiPSC‐CMs) exhibited overall similar morphological and electrophysiological characteristics compared to parental control RhiPSC‐CMs at baseline and with exposure to physiological levels of sodium iodide. Mice were injected intramyocardially with 2 million NIS‐RhiPSC‐CMs immediately following myocardial infarction, and serial positron emission tomography/computed tomography was performed with ¹⁸F‐tetrafluoroborate to monitor transplanted cells in vivo. NIS‐RhiPSC‐CMs could be detected until study conclusion at 8 to 10 weeks postinjection. This NIS‐based molecular imaging platform, with optimal safety and sensitivity characteristics, is primed for translation into large‐animal preclinical models and clinical trials.

Return of secondary findings in genomic sequencing: Military implications

Background

Genomic sequencing has become a widely used tool in clinical and research settings in both civilian and military healthcare systems.

Methods

In this paper, we consider potential military‐specific implications of returning genomic sequencing secondary findings to ensure the proper protections, policies, and processes are in place for the use of this information.

Results

We specifically use two examples to highlight potential military implications of the return of secondary findings.

Conclusion

Clinicians and researchers are strongly encouraged to consider the military implications of the return of results for informed consent of service members or their families undergoing clinical or research genomic sequencing.

Heparin Promotes Cardiac Differentiation of Human Pluripotent Stem Cells in Chemically Defined Albumin-Free Medium, Enabling Consistent Manufacture of Cardiomyocytes

Cardiomyocytes can be differentiated from human pluripotent stem cells (hPSCs) in defined conditions, but efficient and consistent cardiomyocyte differentiation often requires expensive reagents such as B27 supplement or recombinant albumin. Using a chemically defined albumin-free (E8 basal) medium, we identified heparin as a novel factor that significantly promotes cardiomyocyte differentiation efficiency, and developed an efficient method to differentiate hPSCs into cardiomyocytes. The treatment with heparin helped cardiomyocyte differentiation consistently reach at least 80% purity (up to 95%) from more than 10 different hPSC lines in chemically defined Dulbecco's modified Eagle's medium/F-12-based medium on either Matrigel or defined matrices like vitronectin and Synthemax. One of heparin's main functions was to act as a Wnt modulator that helped promote robust and consistent cardiomyocyte production. Our study provides an efficient, reliable, and cost-effective method for cardiomyocyte derivation from hPSCs that can be used for potential large-scale drug screening, disease modeling, and future cellular therapies. Stem Cells Translational Medicine 2017;6:527-538.

Cardiomyopathy induced by sinus tachycardia in combat wounded: a case study

Tachycardia induced cardiomyopathy is a potentially lethal cause of heart failure generally because of atrial tachycardia and less frequently ventricular tachycardia. We present two cases of Marines with severe traumatic blast injuries secondary to improvised explosive device attacks whose hospital courses included amputation, massive blood transfusions, and multiple surgeries. Both patients had prolonged sinus tachycardia averaging >110 beats per minute and developed depressed left ventricular function, which recovered when treated with β blockers. Sinus tachycardia is often considered a physiological response to stress, and the purpose of this manuscript is to describe the cardiac injury apparently related to a prolonged stress response. In addition, the literature does not clearly recommend controlling heart rates in trauma patients with persistent sinus tachycardia, but it is a therapeutic option that should be considered by providers.

Real-time assessment of heart rate variability and loss of control eating in adolescent girls: A pilot study

OBJECTIVE

Studying physiologic underpinnings of loss-of-control (LOC) eating may inform its etiology and contribute to intervention efforts. We therefore examined temporal relationships between autonomic indices [heart rate (HR), heart rate variability (HRV)] and LOC-eating in the natural environment.

METHOD

For two days, adolescents (n = 17, 14.77 ± 1.55 years, BMI-Z 2.17 ± 0.48) with LOC-eating reported on LOC using an electronic device while HR and HRV were assessed continuously using Holter monitoring.

RESULTS

Higher HR and lower HRV in the 30-minutes before eating were significantly associated with LOC-eating overall (p's < 0.001) and at the within-participants level (p's < 0.001), but not at the between-participants level (p's > 0.44). Examined categorically, HR was significantly higher, and HRV significantly lower, prior to high-LOC compared to low-LOC episodes (p's < 0.001).

DISCUSSION

This pilot study suggests that LOC-eating may involve physiologic underpinnings. Additional research with larger samples is needed to further investigate this phenomenon.

Improving clinical practice guidelines for practicing cardiologists

Cardiac-related clinical practice guidelines have become an integral part of the practice of cardiology. Unfortunately, these guidelines are often long, complex, and difficult for practicing cardiologists to use. Guidelines should be condensed and their format upgraded, so that the key messages are easier to comprehend and can be applied more readily by those involved in patient care. After presenting the historical background and describing the guideline structure, we make several recommendations to make clinical practice guidelines more user-friendly for clinical cardiologists. Our most important recommendations are that the clinical cardiology guidelines should focus exclusively on (1) class I recommendations with established benefits that are supported by randomized clinical trials and (2) class III recommendations for diagnostic or therapeutic approaches in which quality studies show no benefit or possible harm. Class II recommendations are not evidence based but reflect expert opinions related to published clinical studies, with potential for personal bias by members of the guideline committee. Class II recommendations should be published separately as "Expert Consensus Statements" or "Task Force Committee Opinions," so that both majority and minority expert opinions can be presented in a less dogmatic form than the way these recommendations currently appear in clinical practice guidelines.

Prognosis and response to therapy of first inpatient and outpatient heart failure event in a heart failure clinical trial: MADIT-CRT

AIMS

Hospitalization for worsening heart failure (HF) is known to increase mortality and morbidity risk and has been frequently used as an endpoint in randomized clinical trials. Whether outpatient management of HF exacerbation carries similar prognostic and therapeutic information is less well known, but could be important for the design of trials that use HF hospitalization as an endpoint.

METHODS AND RESULTS

MADIT-CRT randomized patients with mild HF symptoms to resynchronization therapy vs. control with an average follow-up of 3.3 years and a total of 191 deaths. HF events were centrally adjudicated for receiving i.v. decongestive therapy in an outpatient setting, or an augmented HF regimen during a hospital stay. Patients were compared according to whether their first HF was an out- or inpatient event. The first primary event was non-fatal outpatient HF, non-fatal inpatient HF, and death in 52, 331, and 78 patients, respectively. Patients with inpatient HF tended to be older and more likely to have HF of ischaemic aetiology than subjects who developed outpatient HF events. The risk of death following either type of non-fatal HF events was extremely high [hazard ratio (HR) 12.4, 95% confidence interval (CI) 9.1-16.9 for inpatient HF; HR 10.7, 95% CI 6.1-18.7 for outpatient HF] compared with subjects without non-fatal HF events. Allocation to CRT-D was associated with significant reduction in both types of HF.

CONCLUSION

Outpatient management of worsening HF portends a high risk of death, similar to inpatient HF events, and may be equally sensitive to the effects of therapy. These findings suggest that outpatient HF events should be considered in publicly reported outcomes measures and future HF clinical trials.

TRIAL REGISTRATION

NCT01294449.

Reliability and validity of clinician ECG interpretation for athletes

BACKGROUND

Electrocardiogram (ECG) with preparticipation evaluation (PPE) for athletes remains controversial in the United States and diagnostic accuracy of clinician ECG interpretation is unclear. This study aimed to assess reliability and validity of clinician ECG interpretation using expert-validated ECGs according to the 2010 European Society of Cardiology (ESC) interpretation criteria.

METHODS

This is a blinded, prospective study of diagnostic accuracy of clinician ECG interpretation. Anonymized ECGs were validated for normal and abnormal patterns by blinded expert interpreters according to the ESC interpretation criteria from October 2011 through March 2012. Six pairs of clinician interpreters were recruited from relevant clinical specialties in an academic medical center in March 2012. Each clinician interpreted 85 ECGs according to the ESC interpretation guidelines. Cohen and Fleiss' kappa, sensitivity, and specificity were calculated within specialties and across primary care and cardiology specialty groups.

RESULTS

Experts interpreted 189 ECGs yielding a kappa of 0.63, demonstrating "substantial" inter-rater agreement. A total of 85 validated ECGs, including 26 abnormals, were selected for clinician interpretation. The kappa across cardiology specialists was "substantial" and "moderate" across primary care (0.69 vs 0.52, respectively, P < 0.001). Sensitivity and specificity to detect abnormal patterns were similar between cardiology and primary care groups (sensitivity 93.3% vs 81.3%, respectively, P = 0.31; specificity 88.8% vs 89.8%, respectively, P = 0.91).

CONCLUSIONS

Clinician ECG interpretation according to the ESC interpretation criteria appears to demonstrate limited reliability and validity. Before widespread adoption of ECG for PPE of U.S. athletes, further research of training focused on improved reliability and validity of clinician ECG interpretation is warranted.

QT Variability Index

The QT Variability Index (QTVI) is a non-invasive measure of repolarization lability that has been applied to a wide variety of subjects with cardiovascular disease. It is a ratio of normalized QT variability to normalized heart rate variability, and therefore includes an assessment of autonomic nervous system tone. The approach assesses beat-to-beat variability in the duration of the QT and U wave in conventional surface electrocardiographic recordings, as well as determines the heart rate variability (HRV) from the same recording. As opposed to T wave alternans, QTVI assesses variance in repolarization at all frequencies. Nineteen studies have published data on QTVI in healthy individuals, while 20 have evaluated its performance in cohorts with cardiovascular disease. Six studies have assessed the utility of QTVI in predicting VT/VF, cardiac arrest, or cardiovascular death. A prospective study utilizing QTVI to determine therapy allocation has not been performed, and therefore the final determination of the value of the metric awaits definitive exploration.

Cardiac tamponade in association with anorexia nervosa: a case report and review of the literature

Anorexia nervosa (AN) is a complex psychiatric disorder that can have devastating cardiovascular complications. Its lesser-known association with pericardial effusion has been recently described in the literature. We present the case of a 45 year-old female who presented with a recurrent small bowel obstruction requiring lysis of adhesions and who was found to have a large pericardial effusion that progressed to cardiac tamponade necessitating surgical intervention. The patient had a body mass index of 14.8 kg/m2 (i.e. 71% of ideal body weight) and a long-standing history of food aversion, extreme exercise habits, and weight obsession consistent with AN. To the best of our knowledge, this is the first case of AN-associated cardiac tamponade in the United States, and the first requiring surgical intervention. In conclusion, with this and current data regarding AN-associated pericardial effusions, we recommend a low threshold for performing pre-operative echocardiography for those in whom AN is suspected.

QT variability index on 24-hour Holter independently predicts mortality in patients with heart failure: analysis of Gruppo Italiano per lo Studio della Sopravvivenza nell'Insufficienza Cardiaca (GISSI-HF) trial

BACKGROUND

Increased temporal variability of repolarization, as reflected by QT interval variability measured over 10-15 minutes, predicted spontaneous ventricular arrhythmias and death in implantable cardioverter-defibrillator patients in mild to moderate heart failure (HF).

OBJECTIVE

The purpose of this study was to test our hypothesis that increased mean QT variability over 24 hours would be associated with increased cardiovascular (CV) mortality in a heterogeneous HF population.

METHODS

The Gruppo Italiano per lo Studio della Sopravvivenza nell'Insufficienza Cardiaca-Heart Failure trial prospectively enrolled subjects with HF of any cause. Twenty-four-hour Holter recordings from 268 subjects were analyzed using a template-matching, semiautomatic algorithm to measure QT and heart rate time series in sequential 5-minute epochs over 24 hours. The QT variability index (QTVI) was expressed as the log ratio of the normalized QT variance over normalized heart rate variance. Total and CV mortality were assessed as a function of continuous and dichotomous QTVI (>-0.84) in univariate and multivariable Cox proportional hazards models, adjusting for significant clinical predictors.

RESULTS

After a median of 47 months, there were 53 deaths, of which 44 were from CV causes. A significant association with the outcome was found for QTVI both as continuous and dichotomous variables after adjustment for clinical covariates (age >70, New York Heart Association class III-IV, left ventricular ejection fraction, nonsustained ventricular tachycardia, creatinine): QTVI hazard ratio (HR) 4.0 (confidence interval [CI] 1.8-88; P = .008) for total and 4.4 (CI 1.9-10.1; P = .0006) for CV mortality; QTVI >-0.84 HR 2.0 (CI 1.1-3.6; P = .02) for total and 2.1 (CI 1.1-3.8; P = .02) for CV mortality.

CONCLUSION

Increased repolarization lability, as reflected in QTVI measured over 24 hours, is associated with increased risk for total and CV mortality in a heterogeneous population with chronic HF.

Potassium, Magnesium, and Electrolyte Imbalance and Complications in Disease Management

Electrolyte balance is a critical issue in managing comorbid conditions in both diseased and elderly patients. Patients with hypertension and diabetes need careful regulation of their calcium and magnesium levels, whereas in patients with congestive heart failure, sodium and potassium levels also are critical. Herein we report the outcome of a round table discussion at which issues of renal magnesium clearance, magnesium and arrhythmic risk, ion balance in heart failure, diabetes, ischemic stress, oxidative stress in the cardiomyopathy of magnesium deficiency, roles of magnesium and potassium in bone metabolism and the aging population, and the role of electrolyte balance in hypertension have been discussed. In all these issues the maintaining homeostasis of potassium and magnesium is critical and the various therapies that impact on retaining these ions were discussed. Hallmark studies, i.e., Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial and Studies of Left Ventricular Dysfunction, have provided insight into treatment of patients with cardiovascular and progressive heart failure. These studies and the availability of potassium- and magnesium-sparing diuretics for use in these disorders provide relevant perspectives for treatment.

Diuretic use, progressive heart failure, and death in patients in the DIG study

BACKGROUND

Nonpotassium-sparing diuretics (NPSDs), have been associated with increased sudden cardiac death (SCD) and progressive heart failure (HF) death in HF patients.

METHODS AND RESULTS

In 6797 Digitalis Investigation Group study patients, risk ratios were calculated for death, cardiovascular death (CVD), death from worsening HF, SCD, and HF hospitalization among those taking a potassium-sparing (PSD), NPSD, or no diuretic. Compared with not taking diuretic, risk of death (relative risk [RR] 1.36, 95% confidence interval [CI] 1.17-1.59, P < .0001), CVD (RR = 1.38, 95% CI 1.17-1.63, P = .0001), progressive HF death (RR = 1.41, 95% CI 1.06-1.89, P = .02), SCD (RR = 1.67, 95% CI 1.23-2.27, P = .001), and HF hospitalization (RR = 1.68, 95% CI 1.41-1.99, P < .0001) were increased with NPSD. There was no significant difference in any end point for patients taking only PSD compared to no diuretic. PSD only subjects were less likely than NPSD subjects to be hospitalized for HF (RR = 0.71, 95% CI 0.52-0.96, P = .02).

CONCLUSION

NPSDs are associated with increased risk of death, CVD, progressive HF death, SCD, and HF hospitalization. A randomized trial is needed to assess the role of NPSDs versus PSDs in HF patients.

Symptomatic pericardial constriction without active pericarditis

The decision to undergo pericardectomy for symptomatic pericardial constriction is usually dictated by an image of an abnormal pericardium. We report a case of symptomatic pericardial constriction despite radiographic and pathological evidence of a normal pericardium. The patient was successfully treated with a pericardectomy, with resolution of constrictive hemodynamics and symptoms. Our report suggests that a normal pericardium by computed tomography and biopsy should not preclude pericardectomy for patients who have refractory symptoms, physical findings, and intracardiac pressures diagnostic of constrictive pericarditis.

Diuretic use, progressive heart failure, and death in patients in the Studies Of Left Ventricular Dysfunction (SOLVD)

OBJECTIVES

We sought to determine whether non-potassium-sparing diuretics (PSDs) in the absence of a PSD may result in progressive heart failure (HF).

BACKGROUND

Angiotensin-converting enzyme (ACE) inhibitors incompletely suppress ACE activity in HF patients. Furthermore, non-PSDs are activators of aldosterone secretion. We reasoned that non-PSDs, in the absence of a PSD, might result in progressive HF.

METHODS

In the 6,797 patients in the Studies Of Left Ventricular Dysfunction (SOLVD), we compared the risk of hospitalization for, or death from, HF between those taking a PSD and those who were not, adjusting for known covariates.

RESULTS

The risk of hospitalization from worsening HF in those taking a PSD relative to those taking only a non-PSD was 0.74 (95% confidence interval [CI] 0.55 to 0.99; p = 0.047). The relative risk for cardiovascular death was 0.74 (95% CI 0.59 to 0.93; p = 0.011), for death from all causes 0.73 (95% CI 0.59 to 0.90; p = 0.004), and for hospitalization for, or death from, HF 0.75 (95% CI 0.58 to 0.97; p = 0.030). Compared with patients not taking any diuretic, the risk of hospitalization or death due to worsening HF in patients taking non-PSDs alone was significantly increased (risk ratio [RR] = 1.31, 95% CI 1.09 to 1.57; p = 0.0004); this was not observed in patients taking PSDs with or without a non-PSD (RR = 0.99, 95% CI 0.76 to 1.30; p = 0.95).

CONCLUSIONS

The use of PSDs in HF patients is associated with a reduced risk of death from, or hospitalization for, progressive HF or all-cause or cardiovascular death, compared with patients taking only a non-PSD.

Predisposition to arrhythmia and autonomic dysfunction in Nhlh1-deficient mice

Nhlh1 is a basic helix-loop-helix transcription factor whose expression is restricted to the nervous system and which may play a role in neuronal differentiation. To directly study Nhlh1 function, we generated null mice. Homozygous mutant mice were predisposed to premature, adult-onset, unexpected death. Electrocardiograms revealed decreased total heart rate variability, stress-induced arrhythmia, and impaired baroreceptor sensitivity. This predisposition to arrhythmia is a likely cause of the observed death in the mutant mice. Heterozygosity for the closely related transcription factor Nhlh2 increased the severity of the Nhlh1-null phenotype. No signs of primary cardiac structural or conduction abnormalities could be detected upon necropsy of the null mice. The pattern of altered heart rhythm observed in basal and experimental conditions (stress and pharmacologically induced) suggests that a deficient parasympathetic tone may contribute to the arrhythmia in the Nhlh1-null mouse. The expression of Nhlh1 in the developing brain stem and in the vagal nuclei in the wild-type mouse further supports this hypothesis. The Nhlh1 mutant mouse may thus provide a model to investigate the contribution of the autonomic nervous system to arrhythmogenesis.